Hot-gas reciprocating engine of the kind comprising one or more closed cycles



Nov. 4, 1952 H. DE BREY HOT-GAS RECIPROCATING ENGINE OF THE. KIND COMPRISINC CNE CR MORE CLOSED CYCLES v Filed April 11, 195o BY i AGENT Patented Nov. 4, 1952 HOT-GAS RECIPROCATING VENGINE OF THE KIND COMPRISING ONE OR MORE CLOSED CYCLES Heinrich de Brey, Eindhoven, Netherlands, as-

signor to Hartford National Bank and Trust Company, Hartford, Conn., as trustee Application April 11, 1950, Serial No.'155,334

In the Netherlands April 14, 1949 4 Claims.

This invention relates toy hot-gas reciprocating apparatus. lMore specifically, this invention relates to the arrangement and structure of the cooler and/or the heater of such an apthe velocity of flow of the medium in the cooler, in order that the resistance to ow in the regenerator may be kept within permissible limits. In contradistinction thereto the velocity of now paratus. 5 in the cooler must be high since otherwise the It vis known to use hot-gas reciprocating apheat transfer between medium and cooler wall paratus, such as engines, heat pumps or refrigis unfavourable and the cooling surface, in orerators operating on the reversed hot-gas engine der to compensate therefor, must be so large .principle having one or more closed cycles, in that the clearance space becomes larger than which the hot space and the cold space, associl0 is desirable. In addition with a concentric arated with one cycle of operations, are located in rangement ofall the elements about the cylinvarious cylinders. Such apparatus may be de der, the dimensions of the cooler arerestricted signed so that a piston surface in a given cylinto definite limits, and in the last-mentioned' arder determines the volume of the hot space, rangement, it is furthermore necessary to lead whereas a piston surface in another cylinder dethe flow medium in the desired direction by protermines the volume of the cold space associated viding guide members and similar expedients with the same cycle as the said hot space. between the cooler and the junction duct. How- It has been suggested to house the elements ever, it has been found that such expedients can required for the-operation of the apparatus, (i. e. be designed only with diiiiculty for the velocities the heater, regenerator and cooler) in the chanconcerned. Furthermore, such arrangements nel, connecting the two cylinders, but this arpresent a high resistance to the ow of the rangement has limitations. Firstly, the clearmedium. ance space is large, since the two channels pro- According to the invention, vby housing the viding communication between the cylinder and cooler in theA channel which provides communithe heater or the cooler respectively form a cation between the hot cylinder and the cold clearance space. It is true that the channel itcylinder, the clearance space is reduced as comself is thus done away with as a clearance space pared with that of the known arrangement. between the two cylinders, but the volume of Then, there is provided greater liberty in the this channel will generally not outweigh the adchoice of the cooler dimensions, whilst it is posditional clearance space involved by the said arsible for the cooler to be. designed so that the rangement. Furthermore, the connection of the requirements as to heat transfer and velocity of channel to the cooler presents diiculties from flow are satisfied in the optimum manner. Fur'- the point of view of fluid flow technique. thermore` guide members and similar parts are According to the invention, a hot-gas recipunnecessary, since the form into which the short rocating apparatus, such as an engine, a heat junction duct between regenerator and cooler pump or a refrigerator operating on the reis to be shaped is now determined by the much versed hot-gas engine principle with one or more lowerv velocity of flow through the regenerator closed cycles of operations, in which the hot and can be realized in a manner which is simple space land the cold space associated with one from the point of view of flow technique. cycle of operations are located in diiferent cyl- 40 In one embodiment of the invention the heater inders and which comprise a heater, a regenis preferably made of a group of pipes through erator and a cooler, are characterized in that which the medium flows. Such a heater, known the heater and the regenerator are arranged to per se, provides advantages from a thermodybe concentric with the axis of the cylinder comnamic point of view and i-s structurally simple prising the hot space, while the junction between but its use may involve difficulty, since the dithis cylinder and the cylinder comprising the mension of the cylinder with the heater and associated cold space includes the cooler. heat source with respect to the length thereof The invention provides several advantages. becomes great. However, if this pipe heater is In a known arrangement of the heater, regenused With an apparatus according to the invenerator and cooler, these elements are all ar- 61011, this dfclllty iS mitigated, due to the reranged to be concentric with the cylinder comprising the hot space. With a view to obtaining optimum thermo-dynamic efliciency it is desirable that the velocity of flow of the-medium in theregenerator should. be smallvcompared with moval of the cooler surrounding this cylinder and consequently the length of this cylinder being smaller in this case.

In view of the ground space occupied by the engine, it l1s advantageous, if in accordance 2. A hot gas reciprocating engine comprising rst and second cylinders, said rst cylinder enclosing a hot space, said second cylinder enclosing a cold space, means connecting said hot and cold spaces, said means comprising a heater arranged around the hot space of said first cylinder, a regenerator in communication with said heater and arranged around said first cylinder, and a cooler communicating with said regenerator and said cold space, said cooler being arranged in a conduit extending between said two cylinders, each cylinder also being partially enclosed by another cooler for cooling the running surfaces thereof.

3. A hot gas reciprocating engine comprising a rst cylinder and a second cylinder at right angles thereto, a piston in each cylinder secured to connecting rods mounted on a common crank of a crankshaft, said rst cylinder enclosing a hot space, said second cylinder enclosing a cold space, means connecting said hot and cold spaces, said means comprising a heater arranged around the hot space of said first cylinder, a regenerator in communication with said heater and arranged around said first cylinder, and a cooler communicating with said regenerator and said cold space, said cooler being arranged between said two cylinders.

4. A hot gas reciprocating engine comprising a plurality of cylinders, each cylinder enclosing REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 155,087 Hirsch Sept. 15, 1874 228,716 Woodbury et al. June 8, 1880 1,306,865 Stoddard June 17, 1919 2,484,392 van Heeckeren Oct. 11, 1949 2,486,081 van Weenen Oct. 25, 1949 FOREIGN PATENTS Number Country Date 34,493 Germany Jan. 27, 1886 150,172

Germany Nov. 23, 1901 

